/*
 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package javax.management.relation;

import javax.management.ObjectName;
import javax.management.InstanceNotFoundException;

import java.util.List;
import java.util.Map;

/**
 * The Relation Service is in charge of creating and deleting relation types
 * and relations, of handling the consistency and of providing query
 * mechanisms.
 *
 * @since 1.5
 */
public interface RelationServiceMBean {

  /**
   * Checks if the Relation Service is active.
   * Current condition is that the Relation Service must be registered in the
   * MBean Server
   *
   * @throws RelationServiceNotRegisteredException if it is not registered
   */
  public void isActive()
      throws RelationServiceNotRegisteredException;

  //
  // Accessors
  //

  /**
   * Returns the flag to indicate if when a notification is received for the
   * unregistration of an MBean referenced in a relation, if an immediate
   * "purge" of the relations (look for the relations no longer valid)
   * has to be performed, or if that will be performed only when the
   * purgeRelations method is explicitly called.
   * <P>true is immediate purge.
   *
   * @return true if purges are immediate.
   * @see #setPurgeFlag
   */
  public boolean getPurgeFlag();

  /**
   * Sets the flag to indicate if when a notification is received for the
   * unregistration of an MBean referenced in a relation, if an immediate
   * "purge" of the relations (look for the relations no longer valid)
   * has to be performed, or if that will be performed only when the
   * purgeRelations method is explicitly called.
   * <P>true is immediate purge.
   *
   * @param purgeFlag flag
   * @see #getPurgeFlag
   */
  public void setPurgeFlag(boolean purgeFlag);

  //
  // Relation type handling
  //

  /**
   * Creates a relation type (RelationTypeSupport object) with given
   * role infos (provided by the RoleInfo objects), and adds it in the
   * Relation Service.
   *
   * @param relationTypeName name of the relation type
   * @param roleInfoArray array of role infos
   * @throws IllegalArgumentException if null parameter
   * @throws InvalidRelationTypeException If: <P>- there is already a relation type with that name
   * <P>- the same name has been used for two different role infos <P>- no role info provided <P>-
   * one null role info provided
   */
  public void createRelationType(String relationTypeName,
      RoleInfo[] roleInfoArray)
      throws IllegalArgumentException,
      InvalidRelationTypeException;

  /**
   * Adds given object as a relation type. The object is expected to
   * implement the RelationType interface.
   *
   * @param relationTypeObj relation type object (implementing the RelationType interface)
   * @throws IllegalArgumentException if null parameter or if {@link RelationType#getRelationTypeName
   * relationTypeObj.getRelationTypeName()} returns null.
   * @throws InvalidRelationTypeException if there is already a relation type with that name
   */
  public void addRelationType(RelationType relationTypeObj)
      throws IllegalArgumentException,
      InvalidRelationTypeException;

  /**
   * Retrieves names of all known relation types.
   *
   * @return ArrayList of relation type names (Strings)
   */
  public List<String> getAllRelationTypeNames();

  /**
   * Retrieves list of role infos (RoleInfo objects) of a given relation
   * type.
   *
   * @param relationTypeName name of relation type
   * @return ArrayList of RoleInfo.
   * @throws IllegalArgumentException if null parameter
   * @throws RelationTypeNotFoundException if there is no relation type with that name.
   */
  public List<RoleInfo> getRoleInfos(String relationTypeName)
      throws IllegalArgumentException,
      RelationTypeNotFoundException;

  /**
   * Retrieves role info for given role of a given relation type.
   *
   * @param relationTypeName name of relation type
   * @param roleInfoName name of role
   * @return RoleInfo object.
   * @throws IllegalArgumentException if null parameter
   * @throws RelationTypeNotFoundException if the relation type is not known in the Relation
   * Service
   * @throws RoleInfoNotFoundException if the role is not part of the relation type.
   */
  public RoleInfo getRoleInfo(String relationTypeName,
      String roleInfoName)
      throws IllegalArgumentException,
      RelationTypeNotFoundException,
      RoleInfoNotFoundException;

  /**
   * Removes given relation type from Relation Service.
   * <P>The relation objects of that type will be removed from the
   * Relation Service.
   *
   * @param relationTypeName name of the relation type to be removed
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   * @throws IllegalArgumentException if null parameter
   * @throws RelationTypeNotFoundException If there is no relation type with that name
   */
  public void removeRelationType(String relationTypeName)
      throws RelationServiceNotRegisteredException,
      IllegalArgumentException,
      RelationTypeNotFoundException;

  //
  // Relation handling
  //

  /**
   * Creates a simple relation (represented by a RelationSupport object) of
   * given relation type, and adds it in the Relation Service.
   * <P>Roles are initialized according to the role list provided in
   * parameter. The ones not initialized in this way are set to an empty
   * ArrayList of ObjectNames.
   * <P>A RelationNotification, with type RELATION_BASIC_CREATION, is sent.
   *
   * @param relationId relation identifier, to identify uniquely the relation inside the Relation
   * Service
   * @param relationTypeName name of the relation type (has to be created in the Relation Service)
   * @param roleList role list to initialize roles of the relation (can be null).
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   * @throws IllegalArgumentException if null parameter
   * @throws RoleNotFoundException if a value is provided for a role that does not exist in the
   * relation type
   * @throws InvalidRelationIdException if relation id already used
   * @throws RelationTypeNotFoundException if relation type not known in Relation Service
   * @throws InvalidRoleValueException if: <P>- the same role name is used for two different roles
   * <P>- the number of referenced MBeans in given value is less than expected minimum degree <P>-
   * the number of referenced MBeans in provided value exceeds expected maximum degree <P>- one
   * referenced MBean in the value is not an Object of the MBean class expected for that role <P>-
   * an MBean provided for that role does not exist
   */
  public void createRelation(String relationId,
      String relationTypeName,
      RoleList roleList)
      throws RelationServiceNotRegisteredException,
      IllegalArgumentException,
      RoleNotFoundException,
      InvalidRelationIdException,
      RelationTypeNotFoundException,
      InvalidRoleValueException;

  /**
   * Adds an MBean created by the user (and registered by him in the MBean
   * Server) as a relation in the Relation Service.
   * <P>To be added as a relation, the MBean must conform to the
   * following:
   * <P>- implement the Relation interface
   * <P>- have for RelationService ObjectName the ObjectName of current
   * Relation Service
   * <P>- have a relation id that is unique and unused in current Relation Service
   * <P>- have for relation type a relation type created in the Relation
   * Service
   * <P>- have roles conforming to the role info provided in the relation
   * type.
   *
   * @param relationObjectName ObjectName of the relation MBean to be added.
   * @throws IllegalArgumentException if null parameter
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   * @throws NoSuchMethodException If the MBean does not implement the Relation interface
   * @throws InvalidRelationIdException if: <P>- no relation identifier in MBean <P>- the relation
   * identifier is already used in the Relation Service
   * @throws InstanceNotFoundException if the MBean for given ObjectName has not been registered
   * @throws InvalidRelationServiceException if: <P>- no Relation Service name in MBean <P>- the
   * Relation Service name in the MBean is not the one of the current Relation Service
   * @throws RelationTypeNotFoundException if: <P>- no relation type name in MBean <P>- the relation
   * type name in MBean does not correspond to a relation type created in the Relation Service
   * @throws InvalidRoleValueException if: <P>- the number of referenced MBeans in a role is less
   * than expected minimum degree <P>- the number of referenced MBeans in a role exceeds expected
   * maximum degree <P>- one referenced MBean in the value is not an Object of the MBean class
   * expected for that role <P>- an MBean provided for a role does not exist
   * @throws RoleNotFoundException if a value is provided for a role that does not exist in the
   * relation type
   */
  public void addRelation(ObjectName relationObjectName)
      throws IllegalArgumentException,
      RelationServiceNotRegisteredException,
      NoSuchMethodException,
      InvalidRelationIdException,
      InstanceNotFoundException,
      InvalidRelationServiceException,
      RelationTypeNotFoundException,
      RoleNotFoundException,
      InvalidRoleValueException;

  /**
   * If the relation is represented by an MBean (created by the user and
   * added as a relation in the Relation Service), returns the ObjectName of
   * the MBean.
   *
   * @param relationId relation id identifying the relation
   * @return ObjectName of the corresponding relation MBean, or null if the relation is not an
   * MBean.
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException there is no relation associated to that id
   */
  public ObjectName isRelationMBean(String relationId)
      throws IllegalArgumentException,
      RelationNotFoundException;

  /**
   * Returns the relation id associated to the given ObjectName if the
   * MBean has been added as a relation in the Relation Service.
   *
   * @param objectName ObjectName of supposed relation
   * @return relation id (String) or null (if the ObjectName is not a relation handled by the
   * Relation Service)
   * @throws IllegalArgumentException if null parameter
   */
  public String isRelation(ObjectName objectName)
      throws IllegalArgumentException;

  /**
   * Checks if there is a relation identified in Relation Service with given
   * relation id.
   *
   * @param relationId relation id identifying the relation
   * @return boolean: true if there is a relation, false else
   * @throws IllegalArgumentException if null parameter
   */
  public Boolean hasRelation(String relationId)
      throws IllegalArgumentException;

  /**
   * Returns all the relation ids for all the relations handled by the
   * Relation Service.
   *
   * @return ArrayList of String
   */
  public List<String> getAllRelationIds();

  /**
   * Checks if given Role can be read in a relation of the given type.
   *
   * @param roleName name of role to be checked
   * @param relationTypeName name of the relation type
   * @return an Integer wrapping an integer corresponding to possible problems represented as
   * constants in RoleUnresolved: <P>- 0 if role can be read <P>- integer corresponding to
   * RoleStatus.NO_ROLE_WITH_NAME <P>- integer corresponding to RoleStatus.ROLE_NOT_READABLE
   * @throws IllegalArgumentException if null parameter
   * @throws RelationTypeNotFoundException if the relation type is not known in the Relation
   * Service
   */
  public Integer checkRoleReading(String roleName,
      String relationTypeName)
      throws IllegalArgumentException,
      RelationTypeNotFoundException;

  /**
   * Checks if given Role can be set in a relation of given type.
   *
   * @param role role to be checked
   * @param relationTypeName name of relation type
   * @param initFlag flag to specify that the checking is done for the initialization of a role,
   * write access shall not be verified.
   * @return an Integer wrapping an integer corresponding to possible problems represented as
   * constants in RoleUnresolved: <P>- 0 if role can be set <P>- integer corresponding to
   * RoleStatus.NO_ROLE_WITH_NAME <P>- integer for RoleStatus.ROLE_NOT_WRITABLE <P>- integer for
   * RoleStatus.LESS_THAN_MIN_ROLE_DEGREE <P>- integer for RoleStatus.MORE_THAN_MAX_ROLE_DEGREE <P>-
   * integer for RoleStatus.REF_MBEAN_OF_INCORRECT_CLASS <P>- integer for
   * RoleStatus.REF_MBEAN_NOT_REGISTERED
   * @throws IllegalArgumentException if null parameter
   * @throws RelationTypeNotFoundException if unknown relation type
   */
  public Integer checkRoleWriting(Role role,
      String relationTypeName,
      Boolean initFlag)
      throws IllegalArgumentException,
      RelationTypeNotFoundException;

  /**
   * Sends a notification (RelationNotification) for a relation creation.
   * The notification type is:
   * <P>- RelationNotification.RELATION_BASIC_CREATION if the relation is an
   * object internal to the Relation Service
   * <P>- RelationNotification.RELATION_MBEAN_CREATION if the relation is a
   * MBean added as a relation.
   * <P>The source object is the Relation Service itself.
   * <P>It is called in Relation Service createRelation() and
   * addRelation() methods.
   *
   * @param relationId relation identifier of the updated relation
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if there is no relation for given relation id
   */
  public void sendRelationCreationNotification(String relationId)
      throws IllegalArgumentException,
      RelationNotFoundException;

  /**
   * Sends a notification (RelationNotification) for a role update in the
   * given relation. The notification type is:
   * <P>- RelationNotification.RELATION_BASIC_UPDATE if the relation is an
   * object internal to the Relation Service
   * <P>- RelationNotification.RELATION_MBEAN_UPDATE if the relation is a
   * MBean added as a relation.
   * <P>The source object is the Relation Service itself.
   * <P>It is called in relation MBean setRole() (for given role) and
   * setRoles() (for each role) methods (implementation provided in
   * RelationSupport class).
   * <P>It is also called in Relation Service setRole() (for given role) and
   * setRoles() (for each role) methods.
   *
   * @param relationId relation identifier of the updated relation
   * @param newRole new role (name and new value)
   * @param oldRoleValue old role value (List of ObjectName objects)
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if there is no relation for given relation id
   */
  public void sendRoleUpdateNotification(String relationId,
      Role newRole,
      List<ObjectName> oldRoleValue)
      throws IllegalArgumentException,
      RelationNotFoundException;

  /**
   * Sends a notification (RelationNotification) for a relation removal.
   * The notification type is:
   * <P>- RelationNotification.RELATION_BASIC_REMOVAL if the relation is an
   * object internal to the Relation Service
   * <P>- RelationNotification.RELATION_MBEAN_REMOVAL if the relation is a
   * MBean added as a relation.
   * <P>The source object is the Relation Service itself.
   * <P>It is called in Relation Service removeRelation() method.
   *
   * @param relationId relation identifier of the updated relation
   * @param unregMBeanList List of ObjectNames of MBeans expected to be unregistered due to relation
   * removal (can be null)
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if there is no relation for given relation id
   */
  public void sendRelationRemovalNotification(String relationId,
      List<ObjectName> unregMBeanList)
      throws IllegalArgumentException,
      RelationNotFoundException;

  /**
   * Handles update of the Relation Service role map for the update of given
   * role in given relation.
   * <P>It is called in relation MBean setRole() (for given role) and
   * setRoles() (for each role) methods (implementation provided in
   * RelationSupport class).
   * <P>It is also called in Relation Service setRole() (for given role) and
   * setRoles() (for each role) methods.
   * <P>To allow the Relation Service to maintain the consistency (in case
   * of MBean unregistration) and to be able to perform queries, this method
   * must be called when a role is updated.
   *
   * @param relationId relation identifier of the updated relation
   * @param newRole new role (name and new value)
   * @param oldRoleValue old role value (List of ObjectName objects)
   * @throws IllegalArgumentException if null parameter
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   * @throws RelationNotFoundException if no relation for given id.
   */
  public void updateRoleMap(String relationId,
      Role newRole,
      List<ObjectName> oldRoleValue)
      throws IllegalArgumentException,
      RelationServiceNotRegisteredException,
      RelationNotFoundException;

  /**
   * Removes given relation from the Relation Service.
   * <P>A RelationNotification notification is sent, its type being:
   * <P>- RelationNotification.RELATION_BASIC_REMOVAL if the relation was
   * only internal to the Relation Service
   * <P>- RelationNotification.RELATION_MBEAN_REMOVAL if the relation is
   * registered as an MBean.
   * <P>For MBeans referenced in such relation, nothing will be done,
   *
   * @param relationId relation id of the relation to be removed
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation corresponding to given relation id
   */
  public void removeRelation(String relationId)
      throws RelationServiceNotRegisteredException,
      IllegalArgumentException,
      RelationNotFoundException;

  /**
   * Purges the relations.
   *
   * <P>Depending on the purgeFlag value, this method is either called
   * automatically when a notification is received for the unregistration of
   * an MBean referenced in a relation (if the flag is set to true), or not
   * (if the flag is set to false).
   * <P>In that case it is up to the user to call it to maintain the
   * consistency of the relations. To be kept in mind that if an MBean is
   * unregistered and the purge not done immediately, if the ObjectName is
   * reused and assigned to another MBean referenced in a relation, calling
   * manually this purgeRelations() method will cause trouble, as will
   * consider the ObjectName as corresponding to the unregistered MBean, not
   * seeing the new one.
   *
   * <P>The behavior depends on the cardinality of the role where the
   * unregistered MBean is referenced:
   * <P>- if removing one MBean reference in the role makes its number of
   * references less than the minimum degree, the relation has to be removed.
   * <P>- if the remaining number of references after removing the MBean
   * reference is still in the cardinality range, keep the relation and
   * update it calling its handleMBeanUnregistration() callback.
   *
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server.
   */
  public void purgeRelations()
      throws RelationServiceNotRegisteredException;

  /**
   * Retrieves the relations where a given MBean is referenced.
   * <P>This corresponds to the CIM "References" and "ReferenceNames"
   * operations.
   *
   * @param mbeanName ObjectName of MBean
   * @param relationTypeName can be null; if specified, only the relations of that type will be
   * considered in the search. Else all relation types are considered.
   * @param roleName can be null; if specified, only the relations where the MBean is referenced in
   * that role will be returned. Else all roles are considered.
   * @return an HashMap, where the keys are the relation ids of the relations where the MBean is
   * referenced, and the value is, for each key, an ArrayList of role names (as an MBean can be
   * referenced in several roles in the same relation).
   * @throws IllegalArgumentException if null parameter
   */
  public Map<String, List<String>>
  findReferencingRelations(ObjectName mbeanName,
      String relationTypeName,
      String roleName)
      throws IllegalArgumentException;

  /**
   * Retrieves the MBeans associated to given one in a relation.
   * <P>This corresponds to CIM Associators and AssociatorNames operations.
   *
   * @param mbeanName ObjectName of MBean
   * @param relationTypeName can be null; if specified, only the relations of that type will be
   * considered in the search. Else all relation types are considered.
   * @param roleName can be null; if specified, only the relations where the MBean is referenced in
   * that role will be considered. Else all roles are considered.
   * @return an HashMap, where the keys are the ObjectNames of the MBeans associated to given MBean,
   * and the value is, for each key, an ArrayList of the relation ids of the relations where the key
   * MBean is associated to given one (as they can be associated in several different relations).
   * @throws IllegalArgumentException if null parameter
   */
  public Map<ObjectName, List<String>>
  findAssociatedMBeans(ObjectName mbeanName,
      String relationTypeName,
      String roleName)
      throws IllegalArgumentException;

  /**
   * Returns the relation ids for relations of the given type.
   *
   * @param relationTypeName relation type name
   * @return an ArrayList of relation ids.
   * @throws IllegalArgumentException if null parameter
   * @throws RelationTypeNotFoundException if there is no relation type with that name.
   */
  public List<String> findRelationsOfType(String relationTypeName)
      throws IllegalArgumentException,
      RelationTypeNotFoundException;

  /**
   * Retrieves role value for given role name in given relation.
   *
   * @param relationId relation id
   * @param roleName name of role
   * @return the ArrayList of ObjectName objects being the role value
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation with given id
   * @throws RoleNotFoundException if: <P>- there is no role with given name <P>or <P>- the role is
   * not readable.
   * @see #setRole
   */
  public List<ObjectName> getRole(String relationId,
      String roleName)
      throws RelationServiceNotRegisteredException,
      IllegalArgumentException,
      RelationNotFoundException,
      RoleNotFoundException;

  /**
   * Retrieves values of roles with given names in given relation.
   *
   * @param relationId relation id
   * @param roleNameArray array of names of roles to be retrieved
   * @return a RoleResult object, including a RoleList (for roles successfully retrieved) and a
   * RoleUnresolvedList (for roles not retrieved).
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation with given id
   * @see #setRoles
   */
  public RoleResult getRoles(String relationId,
      String[] roleNameArray)
      throws RelationServiceNotRegisteredException,
      IllegalArgumentException,
      RelationNotFoundException;

  /**
   * Returns all roles present in the relation.
   *
   * @param relationId relation id
   * @return a RoleResult object, including a RoleList (for roles successfully retrieved) and a
   * RoleUnresolvedList (for roles not readable).
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation for given id
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   */
  public RoleResult getAllRoles(String relationId)
      throws IllegalArgumentException,
      RelationNotFoundException,
      RelationServiceNotRegisteredException;

  /**
   * Retrieves the number of MBeans currently referenced in the
   * given role.
   *
   * @param relationId relation id
   * @param roleName name of role
   * @return the number of currently referenced MBeans in that role
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation with given id
   * @throws RoleNotFoundException if there is no role with given name
   */
  public Integer getRoleCardinality(String relationId,
      String roleName)
      throws IllegalArgumentException,
      RelationNotFoundException,
      RoleNotFoundException;

  /**
   * Sets the given role in given relation.
   * <P>Will check the role according to its corresponding role definition
   * provided in relation's relation type
   * <P>The Relation Service will keep track of the change to keep the
   * consistency of relations by handling referenced MBean deregistrations.
   *
   * @param relationId relation id
   * @param role role to be set (name and new value)
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation with given id
   * @throws RoleNotFoundException if: <P>- internal relation <P>and <P>- the role does not exist or
   * is not writable
   * @throws InvalidRoleValueException if internal relation and value provided for role is not
   * valid: <P>- the number of referenced MBeans in given value is less than expected minimum degree
   * <P>or <P>- the number of referenced MBeans in provided value exceeds expected maximum degree
   * <P>or <P>- one referenced MBean in the value is not an Object of the MBean class expected for
   * that role <P>or <P>- an MBean provided for that role does not exist
   * @throws RelationTypeNotFoundException if unknown relation type
   * @see #getRole
   */
  public void setRole(String relationId,
      Role role)
      throws RelationServiceNotRegisteredException,
      IllegalArgumentException,
      RelationNotFoundException,
      RoleNotFoundException,
      InvalidRoleValueException,
      RelationTypeNotFoundException;

  /**
   * Sets the given roles in given relation.
   * <P>Will check the role according to its corresponding role definition
   * provided in relation's relation type
   * <P>The Relation Service keeps track of the changes to keep the
   * consistency of relations by handling referenced MBean deregistrations.
   *
   * @param relationId relation id
   * @param roleList list of roles to be set
   * @return a RoleResult object, including a RoleList (for roles successfully set) and a
   * RoleUnresolvedList (for roles not set).
   * @throws RelationServiceNotRegisteredException if the Relation Service is not registered in the
   * MBean Server
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation with given id
   * @see #getRoles
   */
  public RoleResult setRoles(String relationId,
      RoleList roleList)
      throws RelationServiceNotRegisteredException,
      IllegalArgumentException,
      RelationNotFoundException;

  /**
   * Retrieves MBeans referenced in the various roles of the relation.
   *
   * @param relationId relation id
   * @return a HashMap mapping: <P> ObjectName {@literal ->} ArrayList of String (role names)
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation for given relation id
   */
  public Map<ObjectName, List<String>> getReferencedMBeans(String relationId)
      throws IllegalArgumentException,
      RelationNotFoundException;

  /**
   * Returns name of associated relation type for given relation.
   *
   * @param relationId relation id
   * @return the name of the associated relation type.
   * @throws IllegalArgumentException if null parameter
   * @throws RelationNotFoundException if no relation for given relation id
   */
  public String getRelationTypeName(String relationId)
      throws IllegalArgumentException,
      RelationNotFoundException;
}
